Lengthy post here. Let me know if they should be divided into separate posts. I have 3 sets of questions about my M18Cs regarding the semi-auto function and fps/accuracy.

I have 3 guns - 2 KWA and 1 "JG" KSC clone. Strangely, the clone seems to work the most consistently.... The clone fires fine on semi and full auto while the genuine KWAs have trouble with semi.

I recently bought new slide internals (cylinder, rocket valve, return springs, elevator bar springs, recoil spring, selector switch assembly, hop up, loading ramp) for them and cleaned/lubed everything. Some old parts from the clone were put into one of the genuine KWAs to see if it would alleviate the semi-auto problems.

For some reason, the clone is now experiencing issues with the factory parts and occasionally has issues cycling the slide on semi. It worked perfectly with the original clone parts, so I may just throw those back in.

As for the genuine KWAs though, semi doesn't seem to work on either one, with either genuine KWA factory parts or the clone internals.

QUESTION:
Is this an issue with a slide part, or something in the lower? If anyone could point me in the right direction, or part numbers if you can, I'd greatly appreciate it.

I wanted to increase FPS and accuracy by adding an extended precision barrel with mock [barrel extension] on one of them. Guarder made threaded barrels, but those are long discontinued and super rare. So instead, I have this:http://www.evike.com...oducts_id=35788
but it requires an extended barrel to mount onto.

QUESTION:
Any thoughts on this accessory and the whether it would cause issues since it's clamped directly onto the inner barrel?

They're currently shooting 300-330fps, and my FPG with its extended barrel shoots around 350fps, so I figure I can get my M18C around 370-380 using the following:

QUESTIONS:
Before I hunt down these upgrades, can anyone let me know if 370-380fps is even feasible?
What other parts would I need?
Are all KWA inner barrels compatible with any other KWA gun? for instance, could I put an MK23 barrel in an M18c?

Lastly, i have brand new hopup buckings/bearings in all of them. All parts have been thoroughly cleaned. however, the BBs curve left/right/too high up and one gun's shots drop quickly regardless of the hopup setting. The shots are so unpredictable that it took me 20 shots to hit a target from 15 feet away.

First off, if you're really not sure. I'm sure a mod will chime in and let you know that you can send it back to KWA and have them take a look at it for I think $35 and they promise to have it working for at least 45 days... something like that.

Anyway...

vincewkao, on 06 December 2012 - 01:42 AM, said:

QUESTION:
Is this an issue with a slide part, or something in the lower? If anyone could point me in the right direction, or part numbers if you can, I'd greatly appreciate it.

Assuming your slide is in correct condition as it seems you have just bought new parts, It sounds like there's an issue with the lower. Have you looked at the sears at all? Those are common wear points that will mess with the cycling. It could be the left sear may be broken (i've had that happen to me and it wouldn't allow me to fire in semi without locking up). Also if the right sear is worn, it may work in full-auto but not semi. Or it won't fire when you pull the trigger, it will feel like when you have the selector on neutral. Without looking at the parts directly, I think the issue is going to be with the sears. It's also possible that the disconnector on the left sear may be worn down as well. One more thing to check is the wear on the trigger transfer bar, is the end hitting the sears worn down? Is the bar itself bent in any weird way. You can try bending it so it contacts the right sear better, but that's just a temporary solution.

vincewkao, on 06 December 2012 - 01:42 AM, said:

QUESTION:
Any thoughts on this accessory and the whether it would cause issues since it's clamped directly onto the inner barrel?

This all depends on the inner barrel and [barrel extension] you use. Chances are it shouldn't be a problem, unless you're getting a really heavy mock suppressor and the barrel you chose is really thin. Any hollow suppressor and steel inner barrel should be no problem. PS keep looking for a threaded outter barrel. I recently picked up one (a little beat up), for 20 shipped from a forum.

vincewkao, on 06 December 2012 - 01:42 AM, said:

QUESTIONS:
Before I hunt down these upgrades, can anyone let me know if 370-380fps is even feasible?
What other parts would I need?
Are all KWA inner barrels compatible with any other KWA gun? for instance, could I put an MK23 barrel in an M18c?

It is feasible to get the M18cs up to the 370-380 range. The biggest way to increase your fps is going to be that extended inner barrel. My FPG with a shooters' design inner barrel(150mm) is chronoing at 370-400fps (inconsistent i know). My M18Cs with a madbull inner barrels (92mm) are around 340-350fps. I have a m34 project going, just waiting on a pdi 6.01mm tbb (114mm), should up the fps to about 350-360fps. I'd recommend the PDi 6.01mm barrels for increased FPS, but other say the 6.03mm is bettery for accuracy. Your call on that.

I have tried enhanced rocket valves with no real luck. Infact it lowered the FPS on my FPG, so I stuck with the metal NS2 valves instead. The hammer spring hasn't done anything to really improve my fps either (maybe 1-2fps), but it couldn't hurt anyway.

I've used the magazine shims from ebay, they can be effective in getting an additional 3-5fps. Just watch out for them pushing too much on the rubber and causing the slide to catch a bit. An enhanced recoil spring and spring guide can help with that.

I can't really comment on the REAPS bucking, let me know how that works out for you.

As for high flow valves, I've seen some posts with chrono readings saying quality high flow valves(ie nineball, hurricane, PGC) will increase FPS as much as 10fps. Other says they don't work. My personal experience with the one Hurricane High-Flow I borrowed from a friend showed very little to no difference in fps. Needs more testing.

vincewkao, on 06 December 2012 - 01:42 AM, said:

QUESTION:
What can I do to improve the accuracy/effect of the hopup?

Umm clean it again? Warm soapy water. Also maybe give the new bucking some time to break in? If you're running propane, maybe too much silicone oil and it's getting on the bucking? Could the inner barrel have a problem? I've had one m17 that would just drop too, turned out somehow oil or something got on the bucking. Cleaned it with a paper towel and water and voila hop is back. Can't think of much else sorry.

First off, thanks for your reply. I'm still new to airsoft, so I could use as much guidance as I can get. It would be great if a mod/tech could offer their advice on these upgrades and replacement parts.

thatguyx, on 06 December 2012 - 03:11 PM, said:

First off, if you're really not sure. I'm sure a mod will chime in and let you know that you can send it back to KWA and have them take a look at it for I think $35 and they promise to have it working for at least 45 days... something like that.

Anyway...

I'm aware of the option, but I'm more of a DIY self-tinkerer, despite how painful that can be at times. Plus, I have separation anxiety issues with my babies. I just about never have them on semi auto anyway, so all in all, it's not a huge deal - i just like to fix things.

thatguyx, on 06 December 2012 - 03:11 PM, said:

Assuming your slide is in correct condition as it seems you have just bought new parts, It sounds like there's an issue with the lower. Have you looked at the sears at all? Those are common wear points that will mess with the cycling. It could be the left sear may be broken (i've had that happen to me and it wouldn't allow me to fire in semi without locking up). Also if the right sear is worn, it may work in full-auto but not semi. Or it won't fire when you pull the trigger, it will feel like when you have the selector on neutral. Without looking at the parts directly, I think the issue is going to be with the sears. It's also possible that the disconnector on the left sear may be worn down as well. One more thing to check is the wear on the trigger transfer bar, is the end hitting the sears worn down? Is the bar itself bent in any weird way. You can try bending it so it contacts the right sear better, but that's just a temporary solution.

I don't know what the sears should look like in an unworn state, so i wouldn't be able to tell you whether they're in good condition or not. Likewise for the disconnecter/transfer bar. Looking at the way they function with the slide off, it seems all is in proper order when comparing to the working clone. The strangest thing is, if I put the genuine KWA slide on the clone frame, I still experience the same issue. And with the clone slide on a KWA frame, it fires properly in semi, which leads me to believe it's something slide-related. However, having replaced almost everything in the slide, this just doesn't make any sense.

thatguyx, on 06 December 2012 - 03:11 PM, said:

This all depends on the inner barrel and [barrel extension] you use. Chances are it shouldn't be a problem, unless you're getting a really heavy mock suppressor and the barrel you chose is really thin. Any hollow suppressor and steel inner barrel should be no problem. PS keep looking for a threaded outter barrel. I recently picked up one (a little beat up), for 20 shipped from a forum.

Thanks. I'll check out the forums to see what I can dig up. Nice find - let me know if you ever get tired of it . I was thinking of throwing a noveske amplifier on the front, just for fun - any idea if that has significant impact on a gbb? Not sure if you saw the followup question from my original post or not, but is it possible to use any KWA NS2 barrel in an M series, like an MK23 barrel? Mods - your thoughts?

thatguyx, on 06 December 2012 - 03:11 PM, said:

It is feasible to get the M18cs up to the 370-380 range. The biggest way to increase your fps is going to be that extended inner barrel. My FPG with a shooters' design inner barrel(150mm) is chronoing at 370-400fps (inconsistent i know). My M18Cs with a madbull inner barrels (92mm) are around 340-350fps. I have a m34 project going, just waiting on a pdi 6.01mm tbb (114mm), should up the fps to about 350-360fps. I'd recommend the PDi 6.01mm barrels for increased FPS, but other say the 6.03mm is bettery for accuracy. Your call on that.

i also have a madbull 6.03 inner barrel, but the gun still shoots at 300-325. How did you get it to shoot 350? I have also seen reports saying 6.03 is more accurate than 6.01, but I wonder how that translates when using KSC perfect BBs, since they're smaller than average.

thatguyx, on 06 December 2012 - 03:11 PM, said:

I have tried enhanced rocket valves with no real luck. Infact it lowered the FPS on my FPG, so I stuck with the metal NS2 valves instead. The hammer spring hasn't done anything to really improve my fps either (maybe 1-2fps), but it couldn't hurt anyway.

you may have just saved me a lot of money. $10-$15 each for enhanced valves for each of my 4 guns would have just gone down the drain. buuut, I may buy one just for the satisfaction of having it, because I'm a child like that. Which would you recommend? Angel Customs from evike, or Airsoft Surgeon, or another brand?

thatguyx, on 06 December 2012 - 03:11 PM, said:

I've used the magazine shims from ebay, they can be effective in getting an additional 3-5fps. Just watch out for them pushing too much on the rubber and causing the slide to catch a bit. An enhanced recoil spring and spring guide can help with that.

disappointing to hear that the effects of these are somewhat negligible. It makes sense that a tight seal between mag and nozzle would greatly increase fps. but they're cheap and i already have enhanced recoil springs, so I'll probably just buy a set to test it out anyway.

thatguyx, on 06 December 2012 - 03:11 PM, said:

I can't really comment on the REAPS bucking, let me know how that works out for you.

i hear that they're great for range, but reduce accuracy. Again, I'd be interested in seeing how performance differs between standard BBs and KSC perfects.

thatguyx, on 06 December 2012 - 03:11 PM, said:

As for high flow valves, I've seen some posts with chrono readings saying quality high flow valves(ie nineball, hurricane, PGC) will increase FPS as much as 10fps. Other says they don't work. My personal experience with the one Hurricane High-Flow I borrowed from a friend showed very little to no difference in fps. Needs more testing.

I was thinking of getting the matrix branded ones. I wonder how different they could possible be from the nineball/hurricane/pgc valves. as long as the seal is tight, the physics of it should logically work the same, right? still, with 10 mags and growing, that's another sizeable investment at $16 a pop, plus a valve key for such marginal gains.

thatguyx, on 06 December 2012 - 03:11 PM, said:

Umm clean it again? Warm soapy water. Also maybe give the new bucking some time to break in? If you're running propane, maybe too much silicone oil and it's getting on the bucking? Could the inner barrel have a problem? I've had one m17 that would just drop too, turned out somehow oil or something got on the bucking. Cleaned it with a paper towel and water and voila hop is back. Can't think of much else sorry.

I did run propane, until I bought replacement parts. I've been breaking them in with green gas to see how they fared. Did you chrono your guns using propane or GG? all barrels and buckings were thoroughly cleaned and dried, none have any buildup or lube in them. i'll do some more testing. Tuning these things is a hard skill to learn on your own, so I greatly appreciate your input, and the input of anyone else who offers their thoughts.